package cn.tedu.sp06.fallback;

import cn.tedu.web.util.JsonResult;
import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.stereotype.Component;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;

/*
通过zuul网关,调用后台商品服务失败时,
会执行这段降级代码,向客户端返回降级结果
 */
@Component
public class OrderFB implements FallbackProvider {
    /*
    设置当前降级类,是针对哪个服务的降级类
    - item-service:只针对商品服务降级
    - *:针对所有服务都应用当前降级类
    -null:和*相同
     */
    @Override
    public String getRoute() {
        return "order-service";
    }
/*
发送给客户端的降级结果,封装在 response 对象中
 */
    @Override
    public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
        return new ClientHttpResponse() {
            @Override
            public HttpStatus getStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR; //{code:500,text:"服务器内部错"}
            }

            @Override
            public int getRawStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.value();  //500
            }

            @Override
            public String getStatusText() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase();  //"服务器内部错"
            }

            @Override
            public void close() {
                //用来关闭流
                // BAIS不需要关闭
            }

            @Override
            public InputStream getBody() throws IOException {
                //JsonResult {code:500,msg:"调用商品服务失败,data:null"}
                String json=JsonResult.err().code(500).msg("调用订单服务失败").toString();

                return new ByteArrayInputStream(json.getBytes("UTF-8"));
            }

            @Override
            public HttpHeaders getHeaders() {
                //Content-Type: application/json;charset=UTF-8
                HttpHeaders h=new HttpHeaders();
                h.add("Content-Type", "application/json;charset=UTF-8");
                return h;
            }
        };
    }
}
